JP2017091778A - Negative electrode active material grain powder for nonaqueous electrolyte secondary battery, manufacturing method thereof, and nonaqueous electrolyte secondary battery - Google Patents
Negative electrode active material grain powder for nonaqueous electrolyte secondary battery, manufacturing method thereof, and nonaqueous electrolyte secondary battery Download PDFInfo
- Publication number
- JP2017091778A JP2017091778A JP2015219766A JP2015219766A JP2017091778A JP 2017091778 A JP2017091778 A JP 2017091778A JP 2015219766 A JP2015219766 A JP 2015219766A JP 2015219766 A JP2015219766 A JP 2015219766A JP 2017091778 A JP2017091778 A JP 2017091778A
- Authority
- JP
- Japan
- Prior art keywords
- negative electrode
- active material
- electrode active
- particle powder
- secondary battery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
本発明は、高い充放電初期効率と低い充放電膨張率を有する非水電解質二次電池用負極活物質粒子粉末およびそれを用いた非水電解質二次電池に関するものである。 The present invention relates to a negative electrode active material particle powder for a non-aqueous electrolyte secondary battery having a high initial charge / discharge efficiency and a low charge / discharge expansion coefficient, and a non-aqueous electrolyte secondary battery using the same.
近年、ＡＶ機器やパソコン等の電子機器のポータブル化、コードレス化、ウェアラブル化が急速に進んでおり、これらの駆動用電源として小型、軽量で高エネルギー密度を有する二次電池への要求が高くなっている。このような状況下において、充放電電圧が高く、充放電容量も大きいという長所を有するリチウムイオン二次電池が注目されている。該リチウムイオン二次電池の主要構成材料は正極、非水電解質、セパレーター、負極であり、非水電解質二次電池とも呼ばれている。 In recent years, electronic devices such as AV devices and personal computers are rapidly becoming portable, cordless, and wearable, and a demand for a secondary battery having a small size, light weight, and high energy density as a driving power source is increasing. ing. Under such circumstances, a lithium ion secondary battery having advantages such as a high charge / discharge voltage and a large charge / discharge capacity has attracted attention. The main constituent materials of the lithium ion secondary battery are a positive electrode, a non-aqueous electrolyte, a separator, and a negative electrode, which are also called non-aqueous electrolyte secondary batteries.
該非水電解質二次電池において、負極活物質粒子粉末として黒鉛炭素が、広く用いられているが、その充放電に寄与する容量はすでに理論値（３７２ｍＡｈ／ｇ）に近い値まで到達している。 In the non-aqueous electrolyte secondary battery, graphite carbon is widely used as the negative electrode active material particle powder, but the capacity contributing to charge / discharge has already reached a value close to the theoretical value (372 mAh / g).
さらなる非水電解質二次電池の高密度化を達成するために、比容量の大きな新しい負極活物質粒子粉末が開発されることが急務とされている。そこで、炭素系負極活物質粒子粉末に代わるＳｎ系（理論容量：９９４ｍＡｈ／ｇ）、Ｓｉ系（理論容量：４２００ｍＡｈ／ｇ）などの金属、非金属系負極活物質粒子粉末の検討が行われている。 There is an urgent need to develop a new negative electrode active material particle powder having a large specific capacity in order to achieve higher density of the non-aqueous electrolyte secondary battery. Therefore, investigations have been made on Sn-based (theoretical capacity: 994 mAh / g), Si-based (theoretical capacity: 4200 mAh / g), and other metal and non-metallic negative electrode active material particles instead of carbon-based negative electrode active material particles. Yes.
しかしながら、これらの金属、非金属系負極活物質粒子粉末は、該課題である容量を増大させる長所がある一方、リチウム吸蔵による体積膨張が原因で電極の構造破壊を引き起こす。結果として、二次電池の容量低下に伴いサイクル寿命が短くなる問題が生じる。 However, these metal and non-metallic negative electrode active material particle powders have the advantage of increasing the capacity, which is the problem, but cause structural destruction of the electrode due to volume expansion due to lithium occlusion. As a result, there arises a problem that the cycle life is shortened as the capacity of the secondary battery is reduced.
また、充放電初期効率が低い、即ち不可逆容量が大きいことに起因して、正極と該金属負極活物質粒子粉末を組み合わせる場合に、その不可逆容量分を正極側に充填する必要が生じる。従って、充放電に寄与しない余剰リチウムが二次電池の単位体積当たりのエネルギー密度を低下させる問題を引き起こす。 In addition, due to the low initial charge / discharge efficiency, that is, the large irreversible capacity, when the positive electrode and the metal negative electrode active material particle powder are combined, the irreversible capacity needs to be filled on the positive electrode side. Accordingly, surplus lithium that does not contribute to charging / discharging causes a problem of lowering the energy density per unit volume of the secondary battery.
これまでに、シリコンをはじめとした非金属、又は金属粒子及び非金属酸化物、又は金属酸化物粒子などの負極活物質粒子粉末からなる二次電池を用いる場合、該二次電池内で電気化学的にリチウムをプレドープする様々な手法が提案されている（特許文献１〜４）。充放電に伴う負極の膨張を抑制するために、負極に空隙を作製する方法がある（特許文献１）。不可逆容量分を補うために、予め不可逆容量分の金属リチウムをセパレーターと負極間に備える方法がある（特許文献２）。ＳｉＯｘとグラファイトの混合電極において、セパレーター近傍にＳｉＯｘを配置させ、負極集電体近傍に膨張収縮の少ないグラファイトを配置させ、充放電に付随した電極活物質粒子の膨張収縮による該集電体への応力を緩和させる方法がある（特許文献３）。カーボンナノチューブとＳｉＯｘ負極活物質粒子粉末を機械的に混合する方法がある（特許文献４）。 In the past, when using a secondary battery comprising a non-metal such as silicon, or a negative electrode active material powder such as a metal particle and a non-metal oxide, or a metal oxide particle, Various techniques for pre-doping lithium have been proposed (Patent Documents 1 to 4). In order to suppress expansion of the negative electrode due to charge / discharge, there is a method of forming a void in the negative electrode (Patent Document 1). In order to compensate for the irreversible capacity, there is a method in which metallic lithium for irreversible capacity is provided between the separator and the negative electrode in advance (Patent Document 2). In a mixed electrode of SiO x and graphite, SiO x is disposed in the vicinity of the separator, graphite having little expansion and contraction is disposed in the vicinity of the negative electrode current collector, and the current collector is caused by expansion and contraction of the electrode active material particles accompanying charging and discharging. There is a method of relieving stress on the skin (Patent Document 3). There is a method of mechanically mixing carbon nanotubes and SiO x negative electrode active material particle powder (Patent Document 4).
非水電解質二次電池用の負極活物質粒子粉末として前記諸特性を満たすシリコン系粒子について、現在最も要求されているところであるが、未だ確立されていない。 Silicon-based particles that satisfy the above-mentioned characteristics as negative electrode active material particle powders for non-aqueous electrolyte secondary batteries are currently most demanded, but have not yet been established.
即ち、前記特許文献１〜４のように電気化学的な充電のみによるリチウムのプレドープ技術が検討されているが、いずれにおいても電極にした後に電池作製プロセスの一環としてリチウムを挿入もしくは含有させるものであって、電極構造破壊が抑制されたとは言い難い。また、いずれの方法もプレドープによって不可逆容量は低減できるものの、電池の初回充放電時の粒子の膨張収縮を抑制することは出来ず、電極構造破壊に伴う電極抵抗を上昇させる現象を十分に回避しているとは言い難い。 That is, as described in Patent Documents 1 to 4, lithium pre-doping technology based only on electrochemical charging has been studied. In any case, lithium is inserted or contained as part of the battery manufacturing process after forming an electrode. Therefore, it cannot be said that the electrode structure destruction was suppressed. In either method, the irreversible capacity can be reduced by pre-doping, but the expansion and contraction of the particles during the initial charge / discharge of the battery cannot be suppressed, and the phenomenon of increasing the electrode resistance due to the electrode structure destruction is sufficiently avoided. It's hard to say.
そこで、本発明は、高い充放電初期効率と低い充放電体積膨張率を有する非水電解質二次電池用負極活物質粒子粉末及びその製法、並びに該活物質粒子粉末を具備する非水電解質二次電池を提供することを課題とする。 Accordingly, the present invention provides a negative electrode active material particle powder for a non-aqueous electrolyte secondary battery having a high charge / discharge initial efficiency and a low charge / discharge volume expansion coefficient, a method for producing the same, and a non-aqueous electrolyte secondary comprising the active material particle powder. It is an object to provide a battery.
前記技術的課題は、次の通りの本発明によって達成できる。 The technical problem can be achieved by the present invention as follows.
即ち、本発明は、リチウムとアモルファスシリコンとカーボンナノチューブとを含む複合体であることを特徴とする非水電解質二次電池用負極活物質粒子粉末を提供する。 That is, the present invention provides a negative electrode active material particle powder for a non-aqueous electrolyte secondary battery, which is a composite containing lithium, amorphous silicon, and carbon nanotubes.
本発明の負極活物質粒子粉末において、シリコンに対するリチウムとの原子比が０．７〜４．４を提供する。 In the negative electrode active material particle powder of the present invention, the atomic ratio of lithium to silicon is 0.7 to 4.4.
本発明の負極活物質粒子粉末のラマン分光のスペクトルにおいて、中心波数５００ｃｍ−１〜５２０ｃｍ−１の結晶性シリコンのピーク強度Ｉｐｃと中心波数４４０ｃｍ−１〜４９０ｃｍ−１のアモルファスシリコンのピーク強度Ｉｐａの比Ｉｐｃ／Ｉｐａが０〜６、あるいは結晶性シリコンの積分強度Ｉｃとアモルファスシリコンの積分強度Ｉａの比Ｉｃ／Ｉａが０〜４である負極活物質粒子粉末を提供する。 In the spectrum of the Raman spectroscopy of the negative electrode active material particles of the present invention, the center wavenumber 500cm peak intensity of the crystalline silicon -1 ~520cm -1 I pc and the center wavenumber 440 cm -1 peak intensity of the amorphous silicon ~490cm -1 I Provided is a negative electrode active material particle powder having a pa ratio I pc / I pa of 0 to 6 or a ratio I c / I a of crystalline silicon integrated intensity I c to amorphous silicon integrated intensity I a of 0 to 4 To do.
本発明の負極活物質粒子粉末において、シリコンに対するカーボンナノチューブの重量比が０．００２〜２．５を提供する。 In the negative electrode active material particle powder of the present invention, the weight ratio of carbon nanotubes to silicon is 0.002 to 2.5.
本発明は、カーボンナノチューブを複合させたナノシリコン粒子粉末に対し、電気化学的にリチウムを挿入・脱離して得られる、リチウムとアモルファスシリコンとカーボンナノチューブを含む複合体負極活物質粒子粉末の製造方法を提供する。 The present invention relates to a method for producing a composite negative electrode active material particle powder containing lithium, amorphous silicon, and carbon nanotubes, obtained by electrochemically inserting / extracting lithium to / from nanosilicon particle powder combined with carbon nanotubes I will provide a.
本発明は前記負極活物質粒子粉末を負極に組み込んだ非水電解質二次電池を提供する。 The present invention provides a non-aqueous electrolyte secondary battery in which the negative electrode active material particle powder is incorporated into a negative electrode.
本発明に係る負極活物質粒子粉末は、不可逆容量相当のリチウムを残存させ、且つ、結晶性シリコンをアモルファス化させているので、該負極活物質粒子粉末を用いた非水電解質二次電池は、初期充放電効率が高く、且つ、充放電体積膨張率も低くすることができるので、優れた特性を有する負極活物質粒子粉末として好適である。 Since the negative electrode active material particle powder according to the present invention retains lithium corresponding to the irreversible capacity and makes the crystalline silicon amorphous, the non-aqueous electrolyte secondary battery using the negative electrode active material particle powder is: Since the initial charge / discharge efficiency is high and the charge / discharge volume expansion coefficient can be lowered, it is suitable as a negative electrode active material particle powder having excellent characteristics.
本発明の構成をより詳しく説明すれば次のとおりである。 The configuration of the present invention will be described in more detail as follows.
本発明に係る非水電解質二次電池用負極活物質粒子粉末（以下、「負極活物質粒子粉末」とする。）は、リチウムとアモルファスシリコンとカーボンナノチューブとを含む複合体であることを特徴とする負極活物質粒子粉末である。 The negative electrode active material particle powder for non-aqueous electrolyte secondary battery according to the present invention (hereinafter referred to as “negative electrode active material particle powder”) is a composite containing lithium, amorphous silicon, and carbon nanotubes. Negative electrode active material particle powder.
本発明に係る負極活物質粒子粉末におけるリチウムは、アモルファスシリコン及びカーボンナノチューブのいずれに含まれても良い。また、電気化学的なリチウムの挿入・脱離の際、生成した副生成物が該複合体に含まれても構わず、更には該副生成物にリチウムが含まれても構わない。リチウムの含有量は既知の組成分析により定量できる。更には、不純物として、結晶性シリコン及びカーボンナノチューブ生成させる金属触媒粒子が含まれていても構わない。 Lithium in the negative electrode active material particle powder according to the present invention may be contained in any of amorphous silicon and carbon nanotubes. In addition, during the electrochemical insertion / extraction of lithium, a by-product generated may be included in the complex, and further, the by-product may include lithium. The lithium content can be quantified by known composition analysis. Furthermore, the metal catalyst particle | grains which produce | generate crystalline silicon and a carbon nanotube may be contained as an impurity.
本発明に係る負極活物質粒子粉末におけるアモルファスシリコンは、粉末Ｘ線回折によって同定することが困難であるほど、該粒子内におけるシリコンとしての結晶の周期性が低いものである。アモルファスシリコンと結晶性シリコンの存在比率は、ラマン分光スペクトルの強度比、或いは積分強度比により半定量的な取り扱いが可能である。 As the amorphous silicon in the negative electrode active material particle powder according to the present invention is difficult to identify by powder X-ray diffraction, the periodicity of crystals as silicon in the particle is low. The existing ratio of amorphous silicon and crystalline silicon can be handled semi-quantitatively by the intensity ratio of the Raman spectrum or the integral intensity ratio.
本発明に係る負極活物質粒子粉末におけるカーボンナノチューブは、金属粒子の導電性を確保するものであり、単層カーボンナノチューブ、複層カーボンナノチューブ、多層カーボンナノチューブ、カーボンナノホーン、カーボンナノファイバー等から選ばれる１種または２種類以上の炭素材料を含有しても良い。高分解能の走査型及び透過型電子顕微鏡により該形態の区別をすることができる。 The carbon nanotubes in the negative electrode active material particle powder according to the present invention ensure the conductivity of the metal particles, and are selected from single-walled carbon nanotubes, multi-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanohorns, carbon nanofibers, and the like. You may contain 1 type, or 2 or more types of carbon materials. The morphology can be distinguished by high resolution scanning and transmission electron microscopes.
本発明に係る負極活物質粒子粉末におけるリチウムとアモルファスシリコンとカーボンナノチューブを含む複合状態は、高分解能の走査型及び透過型電子顕微鏡とそれに付随したエネルギー分散型Ｘ線分析（ＥＤＸ）装置により観察及び同定することが可能であり、各々、ナノメートルオーダーで均一に混ざりあっている。 The composite state containing lithium, amorphous silicon and carbon nanotubes in the negative electrode active material particle powder according to the present invention was observed and observed with a high-resolution scanning and transmission electron microscope and an associated energy dispersive X-ray analysis (EDX) apparatus. It is possible to identify them, and each is uniformly mixed in nanometer order.
本発明に係る負極活物質粒子粉末は、リチウムとシリコンとの原子比が０．７〜４．４であることが好ましい。リチウムとシリコンの原子比が０．７を下回る場合、本材料を用いて電池にした場合に不可逆容量を改善する効果が薄くなるので好ましくない。４．４を超える場合には、電池にして充電した際に、正極からのリチウムを受け取れる負極活物質として働かないため好ましくない。 The negative electrode active material particle powder according to the present invention preferably has an atomic ratio of lithium to silicon of 0.7 to 4.4. When the atomic ratio of lithium and silicon is less than 0.7, the effect of improving the irreversible capacity is reduced when a battery is formed using this material, which is not preferable. When exceeding 4.4, it is not preferable because it does not work as a negative electrode active material capable of receiving lithium from the positive electrode when charged as a battery.
本発明に係る負極活物質粒子粉末は、ラマン分光のスペクトルにおいて、中心波数５００ｃｍ−１〜５２０ｃｍ−１の結晶性シリコンのピーク強度Ｉｐｃと中心波数４４０ｃｍ−１〜４９０ｃｍ−１のアモルファスシリコンのピーク強度Ｉｐａの比Ｉｐｃ／Ｉｐａが０〜６、あるいは結晶性シリコンの積分強度Ｉｃとアモルファスシリコンの積分強度Ｉａの比Ｉｃ／Ｉａが０〜４であることが好ましい。ピーク強度比Ｉｐｃ／Ｉｐａが６を超える、あるいは、積分強度比Ｉｃ／Ｉａが４を超える場合、結晶性シリコンの存在比率が非常に高いことを意味し、不可逆容量を改善する効果が薄くなるので好ましくない。 Negative electrode active material particles according to the present invention, in a spectrum of Raman spectroscopy, the center peak intensity of the crystalline silicon wavenumber 500cm -1 ~520cm -1 I pc and the center peak of the amorphous silicon at a wavenumber of 440cm -1 ~490cm -1 it preferably has a specific I pc / I pa intensity I pa is 0-6, or the ratio I c / I a of the integrated intensity I a of the integrated intensity I c and the amorphous silicon crystalline silicon is 0-4. When the peak intensity ratio I pc / I pa exceeds 6 or the integrated intensity ratio I c / I a exceeds 4, it means that the abundance ratio of crystalline silicon is very high, and the effect of improving the irreversible capacity Is not preferable because it becomes thin.
本発明に係る負極活物質粒子粉末において、シリコンに対するカーボンナノチューブの重量比が０．００２〜２．５であることが好ましい。０．００２未満の場合には、得られる負極活物質粒子粉末の電気伝導度を高める効果が不十分となる。２．５を超える場合には、電極にした際の密度が上がらず、高エネルギー密度を実現することが困難となる。好ましくは０．１３〜１．７６である。より好ましくは０．２９〜０．７である。 In the negative electrode active material particle powder according to the present invention, the weight ratio of carbon nanotubes to silicon is preferably 0.002 to 2.5. When it is less than 0.002, the effect of increasing the electrical conductivity of the obtained negative electrode active material particle powder becomes insufficient. If it exceeds 2.5, the density of the electrode does not increase, making it difficult to achieve a high energy density. Preferably it is 0.13-1.76. More preferably, it is 0.29-0.7.
本発明に係る負極活物質粒子粉末は、金属粒子や有機物などを含有しても良い。例えばカーボンナノチューブを成長させるための触媒であるニッケル、コバルト、鉄及びこれらの酸化物、その他化合物を含有しても良い。 The negative electrode active material particle powder according to the present invention may contain metal particles, organic matter, and the like. For example, it may contain nickel, cobalt, iron, oxides thereof, and other compounds that are catalysts for growing carbon nanotubes.
次に、本発明に係る負極活物質粒子粉末の製造方法について述べる。 Next, a method for producing the negative electrode active material particle powder according to the present invention will be described.
本発明に係る負極活物質粒子粉末の原料であるナノシリコン粒子粉末の中位径は、１０ｎｍ〜１０００ｎｍであることが好ましい。ナノシリコン粒子の中位径が１０００ｎｍを超えると、電気化学的な充電・放電に伴う、リチウムの挿入・脱離が困難であり、１０ｎｍ未満であると成型体密度が低くなり、結果として、二次電池のエネルギー密度の低減を招く。好ましくは２０ｎｍ〜５００ｎｍであり、より好ましくは３０ｎｍ〜２００ｎｍである。 The median diameter of the nanosilicon particle powder that is a raw material of the negative electrode active material particle powder according to the present invention is preferably 10 nm to 1000 nm. If the median diameter of the nanosilicon particles exceeds 1000 nm, it is difficult to insert and desorb lithium due to electrochemical charging / discharging, and if it is less than 10 nm, the density of the molded body decreases. The energy density of the secondary battery is reduced. Preferably it is 20 nm-500 nm, More preferably, it is 30 nm-200 nm.
本発明に係る負極活物質粒子粉末の原料であるナノシリコン粒子粉末は、種々の方法で作製される。例えば、プラズマ気相反応法、マイクロシリコン粒子の粉砕法、等を用いることができる。コストの観点から、後者のマイクロ粒子の粉砕法による作製が好ましい。 The nano silicon particle powder which is a raw material of the negative electrode active material particle powder according to the present invention is produced by various methods. For example, a plasma gas phase reaction method, a pulverization method of micro silicon particles, or the like can be used. From the viewpoint of cost, production of the latter microparticles by pulverization is preferred.
本発明に係る負極活物質粒子粉末におけるカーボンナノチューブの混合方法は特に限定されないが、３次元的にシリコン粒子の凝集の隙間まで導電性を確保できることから、メタン直接改質法等による金属触媒含有シリコン粒子へ直接修飾もしくは成長させる方法が好ましい。このときの金属触媒としては、ニッケル、コバルト及び鉄から選ばれる１種又は２種以上が好ましい。金属触媒は、該触媒粒子とナノシリコン粒子の総量に対して０．５〜３０重量％存在させることが好ましい。 The method of mixing the carbon nanotubes in the negative electrode active material particle powder according to the present invention is not particularly limited, but it is possible to ensure conductivity up to the gap between the three-dimensional aggregation of silicon particles. A method of directly modifying or growing the particles is preferred. As a metal catalyst at this time, 1 type, or 2 or more types chosen from nickel, cobalt, and iron is preferable. The metal catalyst is preferably present in an amount of 0.5 to 30% by weight based on the total amount of the catalyst particles and nanosilicon particles.
本発明に係るカーボンナノチューブを複合させたナノシリコン粒子粉末（以下、「前駆体粒子粉末」とする。）は、ナノシリコン粒子と金属触媒を混合し、該混合物に高温(５５０〜８００℃)の炭化水素系ガス(メタン、都市ガス、エタン、プロパン等)雰囲気下でカーボンナノチューブを生成させて、得ることもできる。得られた該前駆体粒子粉末に対し電気化学的にリチウムを挿入・脱離する工程を含んでいる。 The nanosilicon particle powder (hereinafter referred to as “precursor particle powder”) in which the carbon nanotubes according to the present invention are combined is a mixture of nanosilicon particles and a metal catalyst, and the mixture is heated at a high temperature (550 to 800 ° C.). It can also be obtained by producing carbon nanotubes in an atmosphere of hydrocarbon gas (methane, city gas, ethane, propane, etc.). It includes a step of electrochemically inserting and removing lithium from the obtained precursor particle powder.
本発明におけるリチウムの挿入方法及び脱離方法は特に限定されないが、非水電解液中でリチウム源を対極とし、セパレーターを介してディスク状に成形した前駆体粒子粉末を作用極として構成し、電気化学的に充電及び放電処理を施したのちに分解し、該作用極を洗浄・解砕・乾燥することもできる。リチウム源には金属リチウム箔の他、リチウム化合物の成型体など種々の材料が適用できる。 The method for inserting and detaching lithium in the present invention is not particularly limited, and a precursor particle powder formed into a disk shape through a separator is used as a working electrode in a non-aqueous electrolytic solution as a counter electrode. The working electrode can be cleaned, crushed and dried after being chemically charged and discharged and then decomposed. As the lithium source, various materials such as a lithium compound molded body can be applied in addition to the metal lithium foil.
前記充放電に用いられる反応容器の形状は対極のリチウム源と前駆体粒子粉末の成型体が平行に対面していれば特に限定されるものではない。また、用いられるセパレーターは、電解液に対して安定であり保液性に優れていれば特に制限はないが、一般的にはポリエチレン、ポリプロピレン等のポリオレフィン系多孔質シートもしくは不織布が挙げられる。 The shape of the reaction vessel used for the charge / discharge is not particularly limited as long as the counter electrode lithium source and the molded body of the precursor particle powder face each other in parallel. The separator to be used is not particularly limited as long as it is stable with respect to the electrolytic solution and has excellent liquid retention, but generally includes a polyolefin-based porous sheet such as polyethylene and polypropylene, or a nonwoven fabric.
電気化学的にリチウムを挿入及び脱離する際の非水電解液としては、電解質塩及び非水溶媒を含有する。電解質塩としては、例えばリチウム塩であるＬｉＰＦ６、（ＣＦ3ＳＯ2）2ＮＬｉ、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＡｓＦ６、ＣＦ3ＳＯ3Ｌｉ、Ｃ4Ｆ9ＳＯ3Ｌｉ、ＣＦ3ＣＯ2Ｌｉ、（ＣＦ3ＣＯ2）2ＮＬｉ、Ｃ6Ｆ5ＳＯ3Ｌｉ、Ｃ8Ｆ17ＳＯ3Ｌｉ、（Ｃ2Ｆ5ＳＯ2）2ＮＬｉ、（Ｃ4Ｆ9ＳＯ2）（ＣＦ3ＳＯ2）ＮＬｉ、（ＦＳＯ2Ｃ6Ｆ4）（ＣＦ3ＳＯ2）ＮＬｉ、（（ＣＦ3）2ＣＨＯＳＯ2）2ＮＬｉ、（ＣＦ3ＳＯ2）3ＣＬｉ、（３，５−（ＣＦ3）2Ｃ6Ｆ3）4ＢＬｉ、ＬｉＣＦ3、ＬｉＡｌＣｌ4、Ｃ4ＢＯ8Ｌｉなどが挙げられ、これらのうちのいずれか１種又は２種以上が混合して用いられる。 The nonaqueous electrolytic solution used when electrochemically inserting and desorbing lithium contains an electrolyte salt and a nonaqueous solvent. Examples of the electrolyte salt include LiPF 6 , (CF 3 SO 2 ) 2 NLi, LiBF 4 , LiClO 4 , LiAsF 6 , CF 3 SO 3 Li, C 4 F 9 SO 3 Li, and CF 3 CO 2 Li, which are lithium salts. (CF 3 CO 2 ) 2 NLi, C 6 F 5 SO 3 Li, C 8 F 17 SO 3 Li, (C 2 F 5 SO 2 ) 2 NLi, (C 4 F 9 SO 2 ) (CF 3 SO 2 ) NLi, (FSO 2 C 6 F 4 ) (CF 3 SO 2 ) NLi, ((CF 3 ) 2 CHOSO 2 ) 2 NLi, (CF 3 SO 2 ) 3 CLi, (3,5- (CF 3 ) 2 C 6 F 3 ) 4 BLi, LiCF 3 , LiAlCl 4 , C 4 BO 8 Li and the like can be mentioned, and any one or two or more of these can be used in combination.
本発明を実現するのに使用される非水電解液用溶媒としては、非水電解液用として使用しうるものであれば特に制限はない。一般にエチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、γ−ブチロラクトン等の非プロトン性高誘電率溶媒や、ジメチルカーボネート、エチルメチルカーボネート、ジエチルカーボネート、メチルプロピルカーボネート、ジプロピルカーボネート、ジエチルエーテル、テトラヒドロフラン、１，２−ジメトキシエタン、１，２−ジエトキシエタン、１，３−ジオキソラン、スルホラン、メチルスルホラン、アセトニトリル、プロピオニトリル、アニソール、メチルアセテート等の酢酸エステル類あるいはプロピオン酸エステル類等の非プロトン性低粘度溶媒が挙げられる。これらの非プロトン性高誘電率溶媒や非プロトン性低粘度溶媒を適当な混合比で併用することが望ましい。更には、イミダゾリウム、アンモニウム及びピリジニウム型のカチオンを用いたイオン性液体を使用することができる。対アニオンは特に限定されるものではないが、ＢＦ4 -、ＰＦ6 -、（ＣＦ3ＳＯ2）2Ｎ-等が挙げられる。イオン性液体は前述の非水電解液溶媒と混合して使用することができる。 The solvent for non-aqueous electrolyte used for realizing the present invention is not particularly limited as long as it can be used for non-aqueous electrolyte. Generally, aprotic high dielectric constant solvents such as ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, dipropyl carbonate, diethyl ether, tetrahydrofuran, 1,2, -Aprotic low viscosity such as acetate ester or propionate ester such as dimethoxyethane, 1,2-diethoxyethane, 1,3-dioxolane, sulfolane, methylsulfolane, acetonitrile, propionitrile, anisole, methyl acetate A solvent is mentioned. These aprotic high-dielectric constant solvents and aprotic low-viscosity solvents are desirably used in combination at an appropriate mixing ratio. Furthermore, ionic liquids using imidazolium, ammonium and pyridinium type cations can be used. The counter anion is not particularly limited, and examples thereof include BF 4 − , PF 6 − , (CF 3 SO 2 ) 2 N − and the like. The ionic liquid can be used by mixing with the aforementioned non-aqueous electrolyte solvent.
更に、本発明を実現するのに使用される非水電解液中には、必要に応じて各種添加剤を添加してもよい。例えば、イオン導電性被膜の制御を目的としたビニレンカーボネート、メチルビニレンカーボネート、エチルビニレンカーボネート、４−ビニルエチレンカーボネート、フルオロエチレンカーボネートが挙げられる。 Furthermore, various additives may be added to the non-aqueous electrolyte used to realize the present invention as necessary. Examples thereof include vinylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 4-vinylethylene carbonate, and fluoroethylene carbonate for the purpose of controlling the ion conductive film.
更に、本発明を実現するのに使用されるリチウム挿入脱離処理後の負極活物質粒子粉末の成型体を洗浄する洗浄液には、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、γ−ブチロラクトン等の非プロトン性高誘電率溶媒や、ジメチルカーボネート、エチルメチルカーボネート、ジエチルカーボネート、メチルプロピルカーボネート、ジプロピルカーボネート、ジエチルエーテル、テトラヒドロフラン、１，２−ジメトキシエタン、１，２−ジエトキシエタン、１，３−ジオキソラン、スルホラン、メチルスルホラン、アセトニトリル、プロピオニトリル、アニソール、メチルアセテート等の酢酸エステル類あるいはプロピオン酸エステル類等の非プロトン性低粘度溶媒を用いることができる。 Furthermore, the cleaning liquid for cleaning the molded body of the negative electrode active material particle powder after the lithium insertion / extraction treatment used to realize the present invention includes an aprotic such as ethylene carbonate, propylene carbonate, butylene carbonate, and γ-butyrolactone. High dielectric constant solvents, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, dipropyl carbonate, diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,3-dioxolane An aprotic low-viscosity solvent such as acetate or propionate such as sulfolane, methylsulfolane, acetonitrile, propionitrile, anisole or methyl acetate can be used.
次に、本発明に係る非水電解質二次電池について述べる。 Next, the nonaqueous electrolyte secondary battery according to the present invention will be described.
本発明に係る非水電解質二次電池は、正極、負極、非水電解液及びセパレーターから構成される。 The non-aqueous electrolyte secondary battery according to the present invention includes a positive electrode, a negative electrode, a non-aqueous electrolyte, and a separator.
本発明に係る負極活物質粒子粉末を含有する負極を製造する場合には、常法に従って、導電剤と結着剤とを添加混合する。導電剤としてはアセチレンブラック、カーボンブラック、カーボンナノファイバー、黒鉛等の炭素材料が適応できる。しかしながら、本発明に係る負極活物質粒子粉末はカーボンナノチューブを含有する粒子粉末であるため、必ずしも該導電材を混合する必要はない。結着剤としてはポリアミドイミド、ポリイミド、ポリテトラフルオロエチレン、ポリフッ化ビニリデン、アクリル系樹脂等が好ましい。 When manufacturing the negative electrode containing the negative electrode active material particle powder according to the present invention, a conductive agent and a binder are added and mixed according to a conventional method. As the conductive agent, carbon materials such as acetylene black, carbon black, carbon nanofiber, and graphite can be applied. However, since the negative electrode active material particle powder according to the present invention is a particle powder containing carbon nanotubes, it is not always necessary to mix the conductive material. As the binder, polyamideimide, polyimide, polytetrafluoroethylene, polyvinylidene fluoride, acrylic resin, and the like are preferable.
正極活物質としては、一般的な非水電解質二次電池用の正極材であるコバルト酸リチウム、マンガン酸リチウム、ニッケル酸リチウム等を用いることができる。 As the positive electrode active material, lithium cobaltate, lithium manganate, lithium nickelate, or the like, which is a positive electrode material for a general nonaqueous electrolyte secondary battery, can be used.
また、溶媒としては、非水電解液用として使用しうるものであれば特に制限はない。一般にエチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、γ−ブチロラクトン等の非プロトン性高誘電率溶媒や、ジメチルカーボネート、エチルメチルカーボネート、ジエチルカーボネート、メチルプロピルカーボネート、ジプロピルカーボネート、ジエチルエーテル、テトラヒドロフラン、１，２−ジメトキシエタン、１，２−ジエトキシエタン、１，３−ジオキソラン、スルホラン、メチルスルホラン、アセトニトリル、プロピオニトリル、アニソール、メチルアセテート等の酢酸エステル類あるいはプロピオン酸エステル類等の非プロトン性低粘度溶媒が挙げられる。これらの非プロトン性高誘電率溶媒や非プロトン性低粘度溶媒を適当な混合比で併用することが望ましい。更には、イミダゾリウム、アンモニウム及びピリジニウム型のカチオンを用いたイオン性液体を使用することができる。対アニオンは特に限定されるものではないが、ＢＦ4 -、ＰＦ6 -、（ＣＦ3ＳＯ2）2Ｎ-等が挙げられる。イオン性液体は前述の非水電解液溶媒と混合して使用することができる。 Further, the solvent is not particularly limited as long as it can be used for a non-aqueous electrolyte. Generally, aprotic high dielectric constant solvents such as ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, dipropyl carbonate, diethyl ether, tetrahydrofuran, 1,2, -Aprotic low viscosity such as acetate ester or propionate ester such as dimethoxyethane, 1,2-diethoxyethane, 1,3-dioxolane, sulfolane, methylsulfolane, acetonitrile, propionitrile, anisole, methyl acetate A solvent is mentioned. These aprotic high-dielectric constant solvents and aprotic low-viscosity solvents are desirably used in combination at an appropriate mixing ratio. Furthermore, ionic liquids using imidazolium, ammonium and pyridinium type cations can be used. The counter anion is not particularly limited, and examples thereof include BF 4 − , PF 6 − , (CF 3 SO 2 ) 2 N − and the like. The ionic liquid can be used by mixing with the aforementioned non-aqueous electrolyte solvent.
さらに、電解質塩としては、例えばリチウム塩であるＬｉＰＦ６、（ＣＦ3ＳＯ2）2ＮＬｉ、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＡｓＦ６、ＣＦ3ＳＯ3Ｌｉ、Ｃ4Ｆ9ＳＯ3Ｌｉ、ＣＦ3ＣＯ2Ｌｉ、（ＣＦ3ＣＯ2）2ＮＬｉ、Ｃ6Ｆ5ＳＯ3Ｌｉ、Ｃ8Ｆ17ＳＯ3Ｌｉ、（Ｃ2Ｆ5ＳＯ2）2ＮＬｉ、（Ｃ4Ｆ9ＳＯ2）（ＣＦ3ＳＯ2）ＮＬｉ、（ＦＳＯ2Ｃ6Ｆ4）（ＣＦ3ＳＯ2）ＮＬｉ、（（ＣＦ3）2ＣＨＯＳＯ2）2ＮＬｉ、（ＣＦ3ＳＯ2）3ＣＬｉ、（３，５−（ＣＦ3）2Ｃ6Ｆ3）4ＢＬｉ、ＬｉＣＦ3、ＬｉＡｌＣｌ4、Ｃ4ＢＯ8Ｌｉなどが挙げられ、これらのうちのいずれか１種又は２種以上が混合して用いられる。
（実施例）
Further, examples of the electrolyte salt include LiPF 6 , (CF 3 SO 2 ) 2 NLi, LiBF 4 , LiClO 4 , LiAsF 6 , CF 3 SO 3 Li, C 4 F 9 SO 3 Li, and CF 3 CO, which are lithium salts. 2 Li, (CF 3 CO 2 ) 2 NLi, C 6 F 5 SO 3 Li, C 8 F 17 SO 3 Li, (C 2 F 5 SO 2 ) 2 NLi, (C 4 F 9 SO 2 ) (CF 3 SO 2 ) NLi, (FSO 2 C 6 F 4 ) (CF 3 SO 2 ) NLi, ((CF 3 ) 2 CHOSO 2 ) 2 NLi, (CF 3 SO 2 ) 3 CLi, (3,5- (CF 3 ) 2 C 6 F 3 ) 4 BLi, LiCF 3 , LiAlCl 4 , C 4 BO 8 Li, etc., and any one or two of these may be used in combination.
(Example)
本発明の代表的な実施例は、次の通りである。 A typical embodiment of the present invention is as follows.
本発明における負極活物質粒子粉末の複合状態は、試料をアルゴングローブボックス中で大気非曝露測定用容器に充填し、該状態を維持したまま、ＦＥ−ＳＥＭ（日本電子株式会社、ＪＳＭ−７８００Ｆ）にて形状観察及びＥＤＸ装置で組成分析した。 In the composite state of the negative electrode active material particle powder in the present invention, an FE-SEM (JEOL Ltd., JSM-7800F) was used while filling the sample in an atmosphere non-exposure measurement container in an argon glove box and maintaining the state. The composition was analyzed with a shape observation and EDX apparatus.
本発明におけるシリコンに対するリチウムの原子比は、誘導結合プラズマ発光分光分析法（ＩＣＰ−ＡＥＳ、日本ジャーレルアッシュ株式会社製、ＩＲＩＳ Ａｄｖａｎｔａｇｅ）を用いて測定した。試料を灰化した後、酸溶解しリチウム濃度測定用の供試液とした。一方で、試料を灰化、融解した後、酸溶解し、シリコン濃度測定用の供試液とした。 The atomic ratio of lithium to silicon in the present invention was measured using inductively coupled plasma emission spectroscopy (ICP-AES, manufactured by Nippon Jarrell-Ash Co., Ltd., IRIS Advantage). After ashing the sample, the sample was dissolved in acid to prepare a test solution for measuring the lithium concentration. On the other hand, the sample was incinerated and melted, and then dissolved in an acid to prepare a test solution for measuring the silicon concentration.
本発明におけるラマンスペクトルは、試料をアルゴングローブボックス中で大気非曝露測定用容器に充填し、ラマン分光装置（株式会社堀場製作所社製、ＨＲ−Ｅｖｏｌｕｔｉｏｎ）にて励起波長５３２ｎｍのＹＡＧレーザーで測定を行い、得られたスペクトル（各サンプル８〜１０視野）に対し、ガウス関数、ローレンツ関数及び擬フォークト関数（ガウス関数とローレンツ関数組み込み）のいずれかの方法にてフィッティングをかけ、ピーク分離を行い、算術平均した値をピーク強度比Ｉｐｃ／Ｉｐａ、あるいは積分強度比Ｉｃ／Ｉａとした。 The Raman spectrum in the present invention is measured with a YAG laser having an excitation wavelength of 532 nm using a Raman spectrometer (HR-Evolution, manufactured by HORIBA, Ltd.) by filling a sample in a non-atmospheric exposure container in an argon glove box. To the obtained spectrum (8 to 10 fields of view for each sample), fitting by any method of Gaussian function, Lorentz function and pseudo-Forked function (incorporating Gaussian function and Lorentz function) to perform peak separation, The arithmetic average value was used as the peak intensity ratio I pc / I pa or the integrated intensity ratio I c / I a .
本発明におけるシリコンに対するカーボンナノチューブの重量比は、前駆体粒子粉末のシリコンに対するカーボンナノチューブの重量比と相違が無かったため、該値を用いた。炭素・硫黄分析装置（株式会社堀場製作所製、ＥＭＩＡ−９２０Ｖ２）を用いて、炭素量を測定し、カーボンナノチューブの重量とした。 Since the weight ratio of carbon nanotubes to silicon in the present invention was not different from the weight ratio of carbon nanotubes to silicon in the precursor particle powder, this value was used. The amount of carbon was measured using a carbon / sulfur analyzer (manufactured by Horiba, Ltd., EMIA-920V2) to determine the weight of the carbon nanotube.
本発明におけるナノシリコン粒子の中位径は、レーザー回折/散乱式粒子径分布測定装置（株式会社堀場製作所製、ＬＡ−９６０）を用いて測定した。
（実施例１）
＜ナノシリコンへのニッケル触媒担持＞
中位径１５０ｎｍの金属ナノシリコン粉砕粒子２４０ｇに対して、酢酸ニッケル四水和物１７９．５ｇ、水１１６７．５ｇを混合し、ＩＫＡ社製ホモジナイザーＵｌｔｒａ−ｔｕｒｒａｘ Ｔ２５ｄｉｇｉｔａｌを用いて１０分間１５ｋｒｐｍで分散処理を行った。得られた分散液を、日本ビュッヒ社製ミニスプレードライヤーＢ−２９０を用いて入口温度２００℃で噴霧乾燥してニッケル触媒担持した。得られたＮｉ／（Ｎｉ＋Ｓｉ）は１５重量％であった。
The median diameter of the nanosilicon particles in the present invention was measured using a laser diffraction / scattering particle size distribution measuring apparatus (LA-960, manufactured by Horiba, Ltd.).
Example 1
<Supporting nickel catalyst on nanosilicon>
To 240 g of metal nanosilicon pulverized particles having a median diameter of 150 nm, 179.5 g of nickel acetate tetrahydrate and 1167.5 g of water are mixed, and dispersion treatment is performed at 15 krpm for 10 minutes using an IKA homogenizer Ultra-turrax T25 digital. Went. The obtained dispersion was spray-dried at an inlet temperature of 200 ° C. using a mini spray dryer B-290 manufactured by Nihon Büch, and supported on a nickel catalyst. The obtained Ni / (Ni + Si) was 15% by weight.
＜カーボンナノチューブを複合させたナノシリコン粒子粉末（前駆体粒子粉末）の作製＞
得られたニッケル触媒担持のナノシリコン粒子粉末をメタン直接改質装置（株式会社倉本鉄工所製）で６５０℃のメタン雰囲気下で反応させ、シリコンに対するカーボンナノチューブの重量比が０．５である多層カーボンナノチューブを３次元的に生成させ修飾した。
<Preparation of nanosilicon particle powder (precursor particle powder) combined with carbon nanotube>
The resulting nickel catalyst-supported nanosilicon particle powder is reacted in a methane direct reformer (manufactured by Kuramoto Iron Works Co., Ltd.) in a methane atmosphere at 650 ° C., and the weight ratio of carbon nanotubes to silicon is 0.5. Carbon nanotubes were generated and modified three-dimensionally.
＜前駆体粒子粉末への電気化学的なリチウムの挿入及び脱離＞
得られた前駆体粒子粉末を１００ｍｇ計量し、０．１ｍｌのアルコールで湿らせたのち、直径１３ｍｍの金型に入れ、６ＭＰａの圧力で加圧してディスク状の成型体を作製した。得られたディスク状の成型体を１２時間自然乾燥した後、１２時間１１０℃で真空乾燥し、アルゴンドライボックス中で、集電体の銅箔上に成型体を置き、セパレーターを介して対極のリチウム金属箔を置いた。セパレーターにはポリオレフィン製の多孔質シートを用い、非水電解液の電解質に１ＭのＬｉ―ＴＦＳＩ、溶媒にはエチレンカーボネート：ジエチルカーボネート＝１：２（ｖｏｌ％）のものを用いた。かしめ機を用いて２０３２コインセルを作製した。得られたコインセルを東洋システム社製の充放電評価装置ＴＯＳＣＡＴ−３１００にて充放電を行った。まず、２５℃で０．０１Ｃの定電流充電を1ｍＶまで行った後、１ｍＶで０．００１Ｃ もしくは ５００時間の終止条件にて充電を行い、続いて０．００５Ｃ定電流放電を終止電圧１．６Ｖまで行った。この充電時及び放電時の特性曲線を図１に示す。このとき充電容量１７８９ｍＡｈ／ｇ、放電容量は１２４５ｍＡｈ／ｇ、不可逆容量５４４ｍＡｈ／ｇであった。
<Electrochemical Lithium Insertion and Desorption from Precursor Particle Powder>
100 mg of the obtained precursor particle powder was weighed and moistened with 0.1 ml of alcohol, placed in a 13 mm diameter mold, and pressurized with a pressure of 6 MPa to produce a disk-shaped molded body. The obtained disk-shaped molded body was naturally dried for 12 hours and then vacuum-dried at 110 ° C. for 12 hours. The molded body was placed on the copper foil of the current collector in an argon dry box, and the counter electrode was interposed through the separator. Lithium metal foil was placed. A polyolefin porous sheet was used as the separator, 1M Li-TFSI was used as the electrolyte of the non-aqueous electrolyte, and ethylene carbonate: diethyl carbonate = 1: 2 (vol%) was used as the solvent. A 2032 coin cell was produced using a caulking machine. The obtained coin cell was charged / discharged with a charge / discharge evaluation apparatus TOSCAT-3100 manufactured by Toyo System. First, a constant current charge of 0.01 C at 25 ° C. is performed up to 1 mV, then a charge is performed at 1 mV under a termination condition of 0.001 C or 500 hours, and then a 0.005 C constant current discharge is performed at a termination voltage of 1.6 V. Went up. The characteristic curves during charging and discharging are shown in FIG. At this time, the charge capacity was 1789 mAh / g, the discharge capacity was 1245 mAh / g, and the irreversible capacity was 544 mAh / g.
＜充放電処理後の負極活物質粒子粉末の回収と評価＞
充放電処理を完了したディスク状電極が封入されたコインセルをアルゴングローブボックス中で分解し、洗浄溶媒にジメチルカーボネートを用いて、メノウ乳鉢中で解しながら充放電処理後のディスク状の成型体の解砕及び洗浄を行い、自然濾過法にて負極活物質粒子粉末を分離回収し、室温乾燥にて試料を得た。該試料のシリコンに対するリチウムの原子比は２．４６であり、ピーク強度比Ｉｐｃ／Ｉｐａは２．０５であり、積分強度比Ｉｃ／Ｉａは０．９７であった。二次電池評価をすると、不可逆容量が低く、且つ、充放電膨張収縮率が低い値が得られます。
<Recovery and evaluation of negative electrode active material particles after charge / discharge treatment>
Disassemble the coin cell filled with the disk-shaped electrode that has been charged and discharged in an argon glove box, and use the dimethyl carbonate as the cleaning solvent to dissolve the disk-shaped molded body after charging and discharging while dissolving it in an agate mortar. Crushing and washing were performed, and the negative electrode active material particle powder was separated and recovered by natural filtration, and a sample was obtained by drying at room temperature. The atomic ratio of lithium to silicon of the sample was 2.46, the peak intensity ratio I pc / I pa was 2.05, and the integrated intensity ratio I c / I a was 0.97. When evaluating secondary batteries, low irreversible capacity and low charge / discharge expansion / contraction rate can be obtained.
（実施例２）
電気化学的なリチウムの挿入及び脱離において、充電時１３５０ｍＡｈ／ｇの容量で終止し、放電容量８７３ｍＡｈ／ｇ、不可逆容量４７７ｍＡｈ／ｇであったこと以外は、実施例１と同様に試料作製を行った。該試料のシリコンに対するリチウムの原子比は１．７１であった。ピーク強度比Ｉｐｃ／Ｉｐａは０〜６であり、積分強度比Ｉｃ／Ｉａは０〜４であります。二次電池評価をすると、不可逆容量が低く、且つ、充放電膨張収縮率が低い値が得られます。
(Example 2)
Sample preparation was performed in the same manner as in Example 1 except that the insertion and removal of electrochemical lithium terminated at a capacity of 1350 mAh / g during charging, and had a discharge capacity of 873 mAh / g and an irreversible capacity of 477 mAh / g. went. The atomic ratio of lithium to silicon in the sample was 1.71. The peak intensity ratio I pc / I pa is 0-6, and the integrated intensity ratio I c / I a is 0-4. When evaluating secondary batteries, low irreversible capacity and low charge / discharge expansion / contraction rate can be obtained.
（実施例３）
電気化学的なリチウムの挿入及び脱離において、充電時９００ｍＡｈ／ｇの容量で終止し、放電容量５５９ｍＡｈ／ｇ、不可逆容量３４１ｍＡｈ／ｇであったこと以外は、実施例１と同様に試料作製を行った。該試料のシリコンに対するリチウムの原子比は１．２７であった。ピーク強度比Ｉｐｃ／Ｉｐａは０〜６であり、積分強度比Ｉｃ／Ｉａは０〜４であります。二次電池評価をすると、不可逆容量が低く、且つ、充放電膨張収縮率が低い値が得られます。
(Example 3)
Sample preparation was performed in the same manner as in Example 1 except that the insertion and removal of electrochemical lithium terminated at a capacity of 900 mAh / g during charging, and had a discharge capacity of 559 mAh / g and an irreversible capacity of 341 mAh / g. went. The atomic ratio of lithium to silicon in the sample was 1.27. The peak intensity ratio I pc / I pa is 0-6, and the integrated intensity ratio I c / I a is 0-4. When evaluating secondary batteries, low irreversible capacity and low charge / discharge expansion / contraction rate can be obtained.
（比較例１）
実施例１の前駆体粒子粉末を負極活物質粒子粉末として用いた。リチウムとアモルファスシリコンを含有しない粒子粉末である。図４にラマンスペクトルを示すように、中心波数５００ｃｍ−１〜５２０ｃｍ−１の結晶性シリコンのピークのみ観察された。即ち、ピーク強度比Ｉｐｃ／Ｉｐａは６を超えており、積分強度比Ｉｃ／Ｉａは４を超えていた。
(Comparative Example 1)
The precursor particle powder of Example 1 was used as the negative electrode active material particle powder. It is a particle powder that does not contain lithium and amorphous silicon. As shown the Raman spectrum in FIG. 4 it was observed only peaks of crystalline silicon of the center wavenumber 500cm -1 ~520cm -1. That is, the peak intensity ratio I pc / I pa exceeded 6 and the integrated intensity ratio I c / I a exceeded 4.
＜電極作製＞
前記試料を７４重量部、ポリアミドイミド樹脂を２６重量部となるように混合し、Ｎ−メチルピロリドンで希釈して銅箔に塗布し、８０℃で送風乾燥後、得られた電極をプレス機にてプレスを行い、３００℃の窒素雰囲気で１時間硬化させた。
<Electrode production>
74 parts by weight of the sample and 26 parts by weight of polyamideimide resin were mixed, diluted with N-methylpyrrolidone, applied to a copper foil, blown and dried at 80 ° C., and the obtained electrode was put into a press machine. And then cured for 1 hour in a nitrogen atmosphere at 300 ° C.
硬化済みの電極を直径１６ｍｍに打ち抜いて、１１０℃で真空乾燥後、アルゴン雰囲気のグローブボックス中で２０３２コインハーフセルを組み立てた。対極にはリチウム金属、セパレーターにはポリオレフィン系の多孔質シートを用い、非水電解液には電解質に１ＭのＬｉ−ＴＦＳＩ、溶媒にはエチレンカーボネート：ジエチルカーボネート＝１：２（ｖｏｌ％）のものを用いた。 The cured electrode was punched out to a diameter of 16 mm, vacuum-dried at 110 ° C., and then a 2032 coin half cell was assembled in a glove box in an argon atmosphere. Lithium metal is used for the counter electrode, polyolefin porous sheet is used for the separator, 1M Li-TFSI is used for the electrolyte for the non-aqueous electrolyte, and ethylene carbonate: diethyl carbonate = 1: 2 (vol%) for the solvent Was used.
作製したコインセルを東洋システム社製の充放電評価装置ＴＯＳＣＡＴ−３１００にて充放電を行った。まず、２５℃で０．０５Ｃの定電流充電を１ｍＶまで行った後、１ｍＶで０．００５Ｃ もしくは１００時間の終止条件にて充電を行い、続いて０．０５Ｃ定電流放電を終止電圧１．６Ｖまで行った。このとき充電容量２６７０ｍＡｈ／ｇ、放電容量は１５９１ｍＡｈ／ｇ、不可逆量１０７９ｍＡｈ／ｇ、効率５９．６％であった。不可逆容量が約４０％と大きく、負極活物質粒子粉末として好ましくなかった。 The produced coin cell was charged / discharged with a charge / discharge evaluation apparatus TOSCAT-3100 manufactured by Toyo System. First, a constant current charge of 0.05 C at 25 ° C. was performed up to 1 mV, then a charge was performed at a termination condition of 0.005 C or 100 hours at 1 mV, followed by a 0.05 C constant current discharge with a final voltage of 1.6 V. Went up. At this time, the charge capacity was 2670 mAh / g, the discharge capacity was 1591 mAh / g, the irreversible amount was 1079 mAh / g, and the efficiency was 59.6%. The irreversible capacity was as large as about 40%, which was not preferable as the negative electrode active material particle powder.
本発明に係る負極活物質粒子粉末は、不可逆容量相当のリチウムを残存させ、且つ、結晶性シリコンをアモルファス化させているので、当該負極活物質粒子粉末を用いた非水電解質二次電池は、初期充放電効率が高く、且つ、充放電体積膨張率も低くすることができるので、優れた特性を有する負極活物質粒子粉末として好適である。
Since the negative electrode active material particle powder according to the present invention retains lithium corresponding to the irreversible capacity and makes the crystalline silicon amorphous, the non-aqueous electrolyte secondary battery using the negative electrode active material particle powder is Since the initial charge / discharge efficiency is high and the charge / discharge volume expansion coefficient can be lowered, it is suitable as a negative electrode active material particle powder having excellent characteristics.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015219766A JP2017091778A (en) | 2015-11-09 | 2015-11-09 | Negative electrode active material grain powder for nonaqueous electrolyte secondary battery, manufacturing method thereof, and nonaqueous electrolyte secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015219766A JP2017091778A (en) | 2015-11-09 | 2015-11-09 | Negative electrode active material grain powder for nonaqueous electrolyte secondary battery, manufacturing method thereof, and nonaqueous electrolyte secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2017091778A true JP2017091778A (en) | 2017-05-25 |
Family
ID=58768100
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2015219766A Pending JP2017091778A (en) | 2015-11-09 | 2015-11-09 | Negative electrode active material grain powder for nonaqueous electrolyte secondary battery, manufacturing method thereof, and nonaqueous electrolyte secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2017091778A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008027912A (en) * | 2006-07-14 | 2008-02-07 | Kumho Petrochem Co Ltd | Anode active material for lithium secondary cell mixed with carbon nanofiber |
| JP2013510405A (en) * | 2009-11-03 | 2013-03-21 | エンビア・システムズ・インコーポレイテッド | High capacity anode materials for lithium ion batteries |
| US20130177820A1 (en) * | 2012-01-06 | 2013-07-11 | University of Pittsburgh - of the Commonwealth Systems of Higher Education | Silicon-containing compositions, methods of their preparation, and methods of electrolytically depositing silicon on a current carrier for use in lithium ion battery applications |
| WO2014128814A1 (en) * | 2013-02-22 | 2014-08-28 | 株式会社豊田自動織機 | Negative-electrode active substance, method for manufacturing same, and electrical storage device in which same is used |
| JP2015501279A (en) * | 2011-10-25 | 2015-01-15 | コミッサリア ア レネルジー アトミーク エ オ ゼネルジ ザルタナテイヴ | Method for preparing silicon / carbon composites, materials prepared thereby and electrodes comprising such materials, in particular negative electrodes |
| JP2015528985A (en) * | 2012-07-03 | 2015-10-01 | キャタリスト パワー テクノロジーズ インコーポレイテッドＣａｔａｌｙｓｔ Ｐｏｗｅｒ Ｔｅｃｈｎｏｌｏｇｉｅｓ， Ｉｎｃ． | Hybrid energy storage device including support filament |
-
2015
- 2015-11-09 JP JP2015219766A patent/JP2017091778A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008027912A (en) * | 2006-07-14 | 2008-02-07 | Kumho Petrochem Co Ltd | Anode active material for lithium secondary cell mixed with carbon nanofiber |
| JP2013510405A (en) * | 2009-11-03 | 2013-03-21 | エンビア・システムズ・インコーポレイテッド | High capacity anode materials for lithium ion batteries |
| JP2015501279A (en) * | 2011-10-25 | 2015-01-15 | コミッサリア ア レネルジー アトミーク エ オ ゼネルジ ザルタナテイヴ | Method for preparing silicon / carbon composites, materials prepared thereby and electrodes comprising such materials, in particular negative electrodes |
| US20130177820A1 (en) * | 2012-01-06 | 2013-07-11 | University of Pittsburgh - of the Commonwealth Systems of Higher Education | Silicon-containing compositions, methods of their preparation, and methods of electrolytically depositing silicon on a current carrier for use in lithium ion battery applications |
| JP2015528985A (en) * | 2012-07-03 | 2015-10-01 | キャタリスト パワー テクノロジーズ インコーポレイテッドＣａｔａｌｙｓｔ Ｐｏｗｅｒ Ｔｅｃｈｎｏｌｏｇｉｅｓ， Ｉｎｃ． | Hybrid energy storage device including support filament |
| WO2014128814A1 (en) * | 2013-02-22 | 2014-08-28 | 株式会社豊田自動織機 | Negative-electrode active substance, method for manufacturing same, and electrical storage device in which same is used |
Non-Patent Citations (1)
| Title |
|---|
| HU, LIANGBING ET AL., ADVANCED ENERGY MATERIALS, vol. 1, JPN7019002727, 2011, pages 523 - 527, ISSN: 0004102785 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | All-manganese-based Li-ion batteries with high rate capability and ultralong cycle life | |
| Yang et al. | Electrochemical performance of V-doped spinel Li4Ti5O12/C composite anode in Li-half and Li4Ti5O12/LiFePO4-full cell | |
| Wang et al. | Regeneration cathode material mixture from spent lithium iron phosphate batteries | |
| Zhang et al. | Facile fabrication of MnO/C core–shell nanowires as an advanced anode material for lithium-ion batteries | |
| Ruther et al. | Chemical evolution in silicon–graphite composite anodes investigated by vibrational spectroscopy | |
| US10756330B2 (en) | Porous silicon nanostructured electrode and method | |
| Wang et al. | Synthesis and electrochemical properties of La-doped Li4Ti5O12 as anode material for Li-ion battery | |
| TWI797075B (en) | Negative electrode active material, mixed negative electrode active material material, negative electrode for nonaqueous electrolyte secondary battery, lithium ion secondary battery, method for producing negative electrode active material, and method for producing lithium ion secondary battery | |
| JP6241480B2 (en) | Highly dispersible graphene composition and method for producing the same, and electrode for lithium ion secondary battery including highly dispersible graphene composition | |
| US10991971B2 (en) | Negative electrode active material, mixed negative electrode active material, negative electrode for nonaqueous electrolyte secondary battery, lithium ion secondary battery, and, production method of negative electrode active material | |
| TW201703319A (en) | Negative electrode active material for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, and method of producing negative electrode material for a non-aqueous electrolyte secondary battery | |
| TWI705606B (en) | Anode active material, mixed anode active material material, negative electrode for non-aqueous electrolyte secondary battery, lithium ion secondary battery, method for manufacturing negative electrode active material, and method for manufacturing lithium ion secondary battery | |
| Wei et al. | Enhanced electrochemical performance of a LTO/N-doped graphene composite as an anode material for Li-ion batteries | |
| Zhang et al. | Silicon-multi-walled carbon nanotubes-carbon microspherical composite as high-performance anode for lithium-ion batteries | |
| Fan et al. | Nonaqueous synthesis of nano-sized LiMnPO4@ C as a cathode material for high performance lithium ion batteries | |
| TWI753878B (en) | Negative electrode active material, mixed negative electrode active material material, negative electrode for non-aqueous electrolyte secondary battery, lithium ion secondary battery, and method for producing negative electrode active material | |
| JP2016066529A (en) | Negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery | |
| TWI705604B (en) | Anode active material, mixed anode active material material, negative electrode for non-aqueous electrolyte secondary battery, lithium ion secondary battery, method for manufacturing negative electrode active material, and method for manufacturing lithium ion secondary battery | |
| Fang et al. | Facile preparation of Li4Ti5O12/AB/MWCNTs composite with high-rate performance for lithium ion battery | |
| KR102235909B1 (en) | Method for producing negative electrode active material, mixed negative electrode active material, and negative electrode active material | |
| TWI705605B (en) | Anode active material, mixed anode active material material, negative electrode for non-aqueous electrolyte secondary battery, lithium ion secondary battery, method for manufacturing negative electrode active material, and method for manufacturing lithium ion secondary battery | |
| Yu et al. | SnO2 nanoparticles embedded in 3D hierarchical honeycomb-like carbonaceous network for high-performance lithium ion battery | |
| Seng et al. | The effects of FEC (fluoroethylene carbonate) electrolyte additive on the lithium storage properties of NiO (nickel oxide) nanocuboids | |
| Zhao et al. | Urchin-like 3D NiFe2O4 with 1D radially oriented nanorods as anode for lithium-ion based dual-ion pseudocapacitor | |
| Sun et al. | Outstanding Li-storage performance of LiFePO4@ MWCNTs cathode material with 3D network structure for lithium-ion batteries |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20181012 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20190814 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20190828 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20200304 |